My guess is that once you’ve started the return to Earth from the Moon, anything is going to go into a wide solar orbit unless you use fuel to change course and insert into Earth orbit. That’s pretty much the problem the Apollo 13 guys had.
(In other words, they dumped Snoopy sometime after leaving lunar orbit and sometime before Earth orbit insertion.)
Without other knowledge, I would have assumed that they left it in lunar orbit (or crashed it back into the moon like the later ascent sections of the lunar modules) rather than taking 2 extra tons out of lunar orbit with them.